This is such a fresh tasting salad with ribbons of basil leaves throughout. Add dressing in to your liking.
Fill a bowl with ice water. Stir sugar into a large pot filled with water; bring to a boil. Add corn; cook until kernels are softened, about 2 minutes. Drain and transfer corn to ice water until cooled; drain. Cut kernels from the cob with a sharp knife.
Combine corn, Roma tomatoes, red bell pepper, and green onions in a bowl. Stir sour cream, mayonnaise, basil, Parmesan cheese, and cider vinegar together in a bowl until dressing is smooth; season with salt and pepper. Fold dressing into corn mixture. Chill in the refrigerator until flavors combine, 8 hours to overnight.
Per Serving: 277 calories; protein 6.1g; carbohydrates 31.9g; fat 15.9g; cholesterol 16mg; sodium 539.9mg.